639394 has 16 divisors (see below), whose sum is σ = 1108800. Its totient is φ = 270864.

The previous prime is 639391. The next prime is 639433. The reversal of 639394 is 493936.

It is not an unprimeable number, because it can be changed into a prime (639391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1317 + ... + 1735.

It is an arithmetic number, because the mean of its divisors is an integer number (69300).

2⁶³⁹³⁹⁴ is an apocalyptic number.

639394 is a deficient number, since it is larger than the sum of its proper divisors (469406).

639394 is a wasteful number, since it uses less digits than its factorization.

639394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537.

The product of its digits is 17496, while the sum is 34.

The square root of 639394 is about 799.6211603003. The cubic root of 639394 is about 86.1501792739.

The spelling of 639394 in words is "six hundred thirty-nine thousand, three hundred ninety-four".